PROJECT SUMMARY Chronic kidney disease is a growing problem globally, where it now affects more than 10% of the population. In low- and middle-income countries, there is limited data on the actual scope of the problem, however, since it is difficult to obtain reliable estimates of rates of chronic kidney disease for the population, especially in rural or underserved communities. This project will take place in Guatemala, which is a Central American country with a rising rate of chronic kidney disease. Guatemala also has large rural and indigenous Maya populations, and virtually nothing is known about the burden of chronic kidney disease in those populations. This information gap is important for several reasons. One reason is that the indigenous population suffers from very high rates of stunting (short stature), which we hypothesize may be an important risk for developing chronic kidney disease, especially when combined with other traditional risk factors like diabetes or obesity. Another reason is that a surge in kidney disease of uncertain cause (called ?nontraditional? chronic kidney disease) is occurring among young agricultural workers along the Pacific Coast of Guatemala, which appears to be unrelated to diabetes, high blood pressure, or the other usual risk factors that cause kidney disease. In this project, we will take a random sample of adults from two different Guatemalan towns: one with a high proportion of indigenous Maya and a high rate of stunting, one with a low proportion of indigenous Maya but located in the part of Guatemala where the surge in kidney disease of unknown cause is occurring. We will measure the rates of kidney disease, obesity, high blood pressure, and diabetes in these samples. We will also ask questions of each individual about potential exposures and causes of kidney disease. Statistical analysis of this data will allow us to determine the rate of chronic kidney disease in each town, estimate ethnic disparities (indigenous vs nonindigenous) in chronic kidney disease, and explore potential causes of both traditional kidney disease (such as diabetes or stunting) and nontraditional kidney disease. This project represents a concerted effort on the part of our respective institutions in Guatemala and the United States to bridge the ?urban-rural divide? in chronic kidney disease, providing for the first time high- quality, systematic data from rural Guatemala on the impact of this important illness.